This invention relates to the domain of balancing low and medium tonnage ships such as launches, and particularly balancing in roll, in other words in list.
French patent application 2 687 978 deposited by the same applicant describes a device for balancing a ship, particularly for balancing in roll, using a track along which a train of solid weights can move. With reference to FIG. 1 reproducing the system used in this document, the balancing elements are composed of two trains of series of rollers 19 rolling along a track, for example composed of two side rails 25 and 26. A cable 4 driven by a motor 10 through a motor driven drum 9, displaces the rollers 19 on each side of the ship. A blocking system 34 fixing the position using two jaws 37 is placed between the two series of rollers 19, and is controlled by the cable 4. The assembly is fixed in place by bringing the jaws 34 close into contact with a central positioning rail 30 placed longitudinally above the device. When the cable is not tight, the jaws 34 clamp the central positioning rail 30. Two electrical lateral jacks 14 are also used on this device to tension the cable at its two ends through a pulley 5 fixed to the jack rod. Several of these devices may be mounted in parallel to each other in the compartments of the same ship, forming part of the ship deck structure.
It is easy to understand that when the cable is tensioned, the two clamping jaws 37 move apart from each other to release the device from the central positioning rail 30. The set of rollers 19 can then be moved by applying tension to one or the other end of the cable 4. If the tension is removed deliberately or accidentally by the breakage of a strand of the cable 4, the clamping jaws 37 will automatically be blocked in contact with the central positioning rail 30, in the closed position.
Furthermore, French patent application 2 802 504 deposited by the same applicant describes an improvement to this device as shown in FIG. 2. It also comprises a set of moving lead masses 12, together with a pair of jaws 16 at each end bearing on the side rails of a compartment. A single cable 2 pulls the train and controls loosening of the jaws 16.
These ship balancing devices are adapted for high tonnage ships. Application of these devices to medium tonnage and particularly to low tonnage ships would cause a significant loss of volume inside the ship, due to their size. Furthermore, the cable winch control system and the cable tension control system are relatively sophisticated and are not necessary in low tonnage ships. Therefore, the purpose of the invention is to overcome these disadvantages by proposing another ship balancing device applicable to and adapted to low tonnage ships.
Therefore, the main purpose of the invention is a device for balancing a ship, particularly in roll, comprising:
a train of rolling moving masses forming the links of a chain forming a train;
train immobilization means;
a train tension and immobilization means control cable;
at least one motor to activate the train; and
means of adjusting the cable tension in order to control the immobilization means and comprising two moving pulleys to adjust the cable tension.
According to the invention, the moving masses are preformed so that they can wind around at least one drive wheel with teeth that engage in the corresponding complementary housings machined on the side of the moving masses, each of these moving masses rolling on at least two side rails on at least four rollers, the at least two rails forming a U track with two lateral branches each extending along a wall of the ship, and a central horizontal segment, the at least one drive wheel being located inside the turning point formed by the central segment and a first of the two side segments.
In a first preferred embodiment of the invention, it comprises two chain drive wheels, the second being located at the second turning point formed by the central segment and the second of the two side branches.
In one particular embodiment of the invention, the rails are composed of two opposite sides of a section.
In a first embodiment of the invention, the side branches are horizontal, in other words the U formed by the track composed of the two rails is horizontal.
In this case, the moving masses preferably have four wheels and the track is composed of two side rails.
In a second embodiment of the invention, the side branches are vertical, each of the rails is composed of a vertical compartment, in other words the U formed by the track composed of the rails is vertical.
Consequently in this case, the moving masses preferably have eight wheels rolling in sets of four on two inside faces of two opposite sides of the compartment.